This invention relates generally to electronics, and relates more particularly to electronic components and methods of manufacture.
The metal-oxide-semiconductor field-effect-transistor (MOSFET) is an electronic component that has long been used for a wide variety of applications. Power applications, such as printer head drivers, motor controls, anti-lock brake systems, and distributed airbag deployment systems, impose certain requirements on electronic components used in such applications. For example, MOSFETs used in power applications must have high breakdown voltages or, in other words, must be capable of tolerating the high currents and voltages characteristic of power applications without breaking down. High breakdown voltages in MOSFETs have been achieved, for example, by providing epitaxial layers with large thicknesses and low (doping concentration for sustaining the appropriate breakdown voltage. Proper power MOSFET functionality also depends on reducing or eliminating parasitic injection of minority carriers into the substrate when the MOSFET drain goes below the substrate potential. Parasitic substrate injection reduction has been achieved, for example, by heavily doping the substrate such that the minority carriers that cause such parasitic substrate injection have very short diffusion lengths. Thick epitaxial layers, however, tend to increase the minority carrier diffusion lengths, thus interfering with the ability of the heavily doped substrate to reduce parasitic substrate injection. Although silicon-on-insulator (SOI) platforms have proven effective in providing high breakdown voltages and in eliminating parasitic minority carrier substrate injection, the design complexity, higher wafer cost, and lower heat removal capability of SOI technology make the use of SOI platforms problematic for many applications. Accordingly, there exists a need for a non-SOI electronic component capable of providing the high breakdown voltages and low parasitic minority carrier substrate injection necessary for power applications.